According to the technical background there are a number of different duvets intended to keep a person warm when he or she sleeps. A problem has been that the duvet slips down so that shoulders and arms are exposed which causes them to cool down. This can be experienced as troublesome, especially if one has sensitive shoulders and arms.
U.S. Pat. No. 1,291,191 describes a duvet which is fastened around the neck of a little child so that the child can not kick the duvet off itself. As the duvet is fastened around the neck, it prevents cold from reaching the neck and the arms. However, this also makes it easy to feel confined.
GB Patent No. 578,893 describes a similar duvet as in U.S. Pat. No. 1,291,191, with a small difference in how the duvet is fastened around the neck. Also here, it is easy to feel confined.
U.S. Pat. No. 4,653,131 describes a duvet which by means of straps is fastened in the bed frame to hold a person who lies in the bed in place. This duvet is principally intended for holding children or senile persons in a safe way in bed during the night. For natural reasons, the duvet must then lay very tight over the body and thus markedly limits the freedom of movement of the person.
U.S. Pat. No. 4,441,223 describes a duvet which has a hole in the upper part of the duvet. The hole is adapted for to be able to pass a persons head therethrough. During use, the head will keep the duvet in place against the bed so that the duvet can not fall off the bed and the person is by that always kept warm. There is a great risk that a person who uses this duvet feels confined and limited in hers/his freedom of movement during sleep.
US Patent Application No. 2002/0157184 shows as U.S. Pat. No. 4,441,223 a duvet which has a hole in the upper part of the duvet. The only difference is the design of the hole and its placing. Also here there is a risk that a person may feel confined and limited in hers/his freedom of movement.
U.S. Pat. No. 1,403,873 describes a duvet for babies which consists of a lower part which the baby lies on and an upper part which may be folded over the baby. The upper part has an aperture for the neck and for the hands. During use, the baby is confined and has apart from the legs a limited freedom of movement.
As is evident from the known art, they all solve more or less the problem of keeping the person under the duvet warm. However, the problem with the known solutions is that they limit the freedom of movement of the person lying under the duvet, i.e. it feels a bit like being confined.